Certain automatic tuning systems for stringed instruments have been described in the art.
U.S. Pat. No. 5,824,929 issued Oct. 20, 1998 to Freeland et al. for “Musical Instrument Self-Tuning System with Calibration Library describes an automatic open-loop self-tuning system using a library of calibration functions for setting an actuator position for tuning a stringed instrument under different sets of conditions, e.g., temperature, humidity, and instrument characteristics. This patent relies on art-known actuators to effect the tuning corrections. It uses “open-loop feedback” in the sense that it stores actuator settings from a previous tuning correction and uses them in a subsequent tuning correction. U.S. Pat. No. 5,859,378 issued Jan. 12, 1999 to Freeland et al., for “Musical Instrument Self-Tuning System with Capo Mode” discloses methods for calculating tuning adjustments required to tune a stringed instrument after installation of a capo. It relies on art-known mechanical configurations for actually changing string frequencies.
U.S. Pat. No. 5,767,429 issued Jun. 16, 1998 to Milano et al. for “Automatic String Instrument Tuner” describes an automatic tuning system using closed-loop feedback and a motor and gear arrangement with a transmission to successively apply the motor output to different strings. U.S. Pat. No. 5,343,793 issued Sep. 6, 1994 to Pattie for “Automatically Tuned Musical Instrument” discloses an automatic tuning system having motors to adjust string tension by winding the string around the motor shaft. This system uses “closed-loop feedback” in that it does not refer to stored actuator positions in making frequency adjustments. U.S. Pat. No. 5,323,680 issued Jun. 28, 1994 to Miller et al for “Device and Method for Automatically Tuning a Stringed Musical Instrument” discloses a tuning mechanism that uses a linear actuator to deflect a string sideways to adjust its frequency. U.S. Pat. No. 5,065,660 issued Nov. 19, 1991 to deBuda for “Piano Tuning System” provides a handheld device for adjusting piano string tension in response to closed-loop feedback. U.S. Pat. No. 4,909,126 issued Mar. 20, 1990 to Skinn et al. for “Automatic Musical Instrument Tuning System” describes a lever arm and roller assembly for adjusting string tension. No drive gear/string cam components are disclosed. U.S. Pat. No. 4,803,908 issued Feb. 14, 1989 to Skinn et al. for “Automatic Musical Instrument Tuning System” discloses adjusting string tension by means of a dowel pin with levers and rollers. No drive gear/string cam components are used. U.S. Pat. No. 4,856,404 issued Aug. 15, 1989 to Hughes, Sr. for “Guitar with Tuning Changing, Key Changing, Chord Changing and Modulating Capabilities discloses a tuning method requiring manual adjustment of string tension. U.S. Pat. No. 4,535,670 issued Aug. 20, 1985 to Borisoff for “String Bender Attachment Construction” also discloses a manual system for changing string tension. U.S. Pat. No. 4,584,923 issued Apr. 29, 1986 to Minnick for “Self Tuning Tail Piece for String Instruments” discloses an automatic tuning device using closed-loop feedback and acme screws and levers to adjust tension. U.S. Pat. No. 4,426,907 issued Jan. 24, 1984 to Scholz for “Automatic Tuning Device” discloses an automatic tuning device that works by sensing string tension rather than frequency. U.S. Pat. No. 4,375,180 issued Mar. 1, 1983 to Scholz for “Automatic Tuning Device” also discloses an automatic tuning device that works by sensing string tension rather than frequency. U.S. Pat. No. 4,088,052 issued May 9, 1978 to Hedrick for “String Instrument Tuning Apparatus” discloses a separate handheld tuning device actuated by a cable system.
A number of patents disclose tuning systems having means for producing vibrato effects. U.S. Pat. No. 6,415,584 issued Jul. 9, 2002 to Whittall et al. for “Tuning Means for Tuning Stringed Instruments, a Guitar Comprising Tuning Means and a Method of tuning Stringed Instruments” discloses a multistage epicyclic gearbox where the string wraps around the output peg for tension adjustment. It discloses the use of a fulcrum-style vibrato. device. U.S. Pat. No. 5,886,270 issued May 23, 1999 to Wynn for “Electromechanical Tuner for Stringed Instruments: also discloses a fulcrum-style vibrato device using a double-hinged tremolo system. U.S. Pat. No. 4,390,579 issued Feb. 21, 1995 to Burgon for “Tuning of Musical Instruments” discloses the use of a spring to tension the strings and a moveable carriage that runs on a rack to produce vibrato effects. U.S. Pat. No. 5,038,657 issued Aug. 13, 1991 to Busley for “String Tensioning Apparatus for a Musical Instrument” discloses an automatic tuning system comprising motors with shafts around which strings are wound to adjust tension. It has a joystick device simulating a conventional vibrato arm or a joyball that electronically controls vibrato effects. U.S. Pat. No. 5,095,797 issued Mar. 17, 1992 to Zacaroli for “Automatic Tone Control for Stringed Musical Instruments” discloses a tuning systems that uses shape memory metal to control string tension and resistors to produce tremolo effects. U.S. Pat. No. 4,160,401 issued Jul. 10, 1979 to Tomioka for “String Vibration Transducer Bridge for Electric Stringed Instruments” discloses a piezoelectric pushing mechanism for adjusting string tension. Tremolo can be applied through the use of resistors. U.S. Pat. No. 5,438,902 issued Aug. 8, 1995 to Baker for “Memory Tuning System for String Instruments” discloses a tuning device using levers and cams and capable of providing vibrato effects by activating a bar that tilts a tremolo base element. U.S. Pat. No. 5,009,142 issued Apr. 23, 1991 to Kurtz for “Means and Method for Automatic Resonance Tuning” discloses an automatic tuning device that uses piezoelectric pushers to adjust string tension, and creates vibrato effects by changes in voltage.
Further U.S. patents disclose tuning systems that involve communication of system components with remote components. U.S. Pat. No. 6,278,047 issued Aug. 21, 2001 to Cumberland for “Apparatus for Tuning Stringed Instruments” discloses a tuning device that works by sensing tension on a string rather than frequency. It can be wirelessly connected to a computer connected to the drivers that tighten the string. U.S. Pat. No. 6,184,452 issued Feb. 6, 2001 to Long et al. for “Tuning of Musical Instruments” discloses the use of a single motor and clutch system to drive output screws for applying string tension. No strumming of the strings is required. The tuning device may be operated by remote control. U.S. Pat. No. 6,166,307 issued Dec. 26, 2000 to Caulkins et al. for “Apparatus for Automating a Stringed Instrument” discloses a stringed instrument in which an outside computer can control tuning by conventional means without the need for manually strumming the strings. U.S. Pat. No. 4,338,846 issued Jul. 13, 1982 to Pogoda for “Remote Control for Electronic Musical Instrument Equipment” discloses a manually operated switch located on an electric guitar that controls a remotely located tuning device through the existing guitar cable. It does not disclose string-tensioning mechanisms.
U.S. Patent Publication No. 2003/0177894 published Sep. 25, 2003 of Skinn for “Piezo Rocker Bridge” discloses a moveable-saddle bridge having rocker components for allowing substantially frictionless string movement as string tension is adjusted. Also disclosed are piezoelectric pickup designs to allow automatic tuning devices to be operated by strumming all strings at once.
Other patents relevant to automatic tuning systems include U.S. Pat. Nos. 3,144,802, 4,044,239, 4,196,652, 4,947,726, 4,958,550, 4,207,791, 4,313,361, 4,732,071, 4,327,623, 2,136,627, 4,100,832, 4,434,696, 4,457,203, 4,512,232, and 4,665,790.
All publications referred to herein are incorporated by reference to the extent not inconsistent herewith for their teachings of various devices and methods useful in this invention. Any feature disclosed in any such publication that is not specifically disclosed in the following description of the present invention may be excluded in embodiments of this invention.